Grinding-mill.



PATBNTED MAY 24, 1904.

G. G. PRENZEL.

GRINDING MILL.

APPLICATION IILED JULY 10, 1903.

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PATBNTED MAY 24, 1904.

G. O. PRENZEL. GRINDING MILL.

APPLICATION rmm JULY 10, 1903.

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INVENTOH 6 601 929 CZJrezzzeZ M A 770/?NE VS cylinder supported at one end by legs 2 and UNITED STATES Patented May 24, 1904.

PATENT OFFICE.

GEORGE C. PRENZEL, OF

FRANKLIN, TEN N ESSEE.

GRINDING-MILL.

To all whom it may concern.-

Be it known that I, GrEoRe-E (J. PRENZEL, a citizen of the United States, and a resident of Franklin, in the county of Williamson and State of Tennessee, have invented a new and Improved (arrindingMill, of which the following is a full, clear, and exact description.

I This invention relates to improvements in grinding-mills designed for use in connection with roller flour-mills, and particularly adapted for grinding pure middlings, fine flat middlings, fiat tailings, and lowgrade stock, an

object being to provide a machine of this character of simple construction and by means of which the work may be rapidly and thoroughly done.

I will describe a grinding-mill embodying my invention and then point out the novel features in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure l is a sectional elevation of a grinding-mill embodying my invention. Fig. 2 is a plan View thereof. Fig. 3 is a perspective View of a shaft-bearing employed. Fig. 4 is a rear end view, and Fig. 5 is a sectional view of grinding-rings employed.

Referring to the drawings, 1 designates a at the opposite end by a hopper 3, with which said cylinder communicates. Extended through the cylinder and through the hopper is a guiding-shaft 4, on which is mounted within the cylinder a grinding-roll 5. This grinding-roll is tapered in opposite directions from a point between its ends. The rear tapered portion is provided with spirally-disposed corrugations 6, and the correspondinglyshaped interior surface of the cylinder is also provided with longitudinal corrugations. At its opposite tapered portion or feed end the roll is provided with a spiral feeding-blade 7, and above this feeding-blade the cylinder is provided with an inlet 8 for material to be ground. Secured by means of screws to the outlet end of the roll is a corrugated grindingring 9, which coacts with a corrugated grinding-ring 10, secured by means of screws to Patent No. 760,481, dated May 24, 1904. Serial No. 164,962. (No model.)

the outlet end of the cylinder. These rings are made of hard material-such, for instance, as steel-and they are made removable, so that rings having different degrees of corrugations may be employed, as occasion may require, and it will be noted that the ring 9 1s tapered, and the interior surface of the ring 10 is correspondingly shaped. At its forward end the shaft 41 has a bearing in a boxing 11, and at its rear end it has a bearing in a boxing consisting of a lower member 12 and an upper member 13. These members are supported in brackets 14:, attached to the outer surface of the hopper 3, and as a means for adjusting the bearing vertically I employ set-screws 15, which extend through the up per and lower walls of the brackets, and the bearing maybe adjusted laterally by means of set-screws 16, which extend through the side walls of the brackets. By this means the roller may be adjusted or alined within the cylinder. Extended outward from the lower member 12 of the bearing is a frame 17 in the end wall 18 of which is an opening through which an adjusting-screw 19 passes, the said screw being provided at its outer end with a handwheel 20,and at the inner side of the wall 18 of said frame is a jam-nut 21 for holding the screw as adjusted. This screw passes loosely through a block 22, arranged on which is a bearing 23 for the end of the shaft 4:. A nut 24: engages with the screw 19 and is movable in a guideway 25, formed in thelower bearing member 12. This guideway will prevent the rotary motion of said nut when the screw is rotated for adjusting the tension of a spring 26, arranged between said nut and the block 22. Also engaging with the screw 19 and bearing against the rear side of the block 22 is a jamnut 27. By this arrangement .it is obvious that the grinding-roll will be adjusted relatively to the interior of the cylinder, and it will be held yieldingly in position by means of the spring 26.

This machine when used in flour-mills relieves the rolls of the fluify stock, which has a tendency to cushion them and reduces their grinding capacity. At the same time the mill produces a very fine granular flour.

' Having thus described my invention, I

claim as new and desire to secure by Letters Patent 1. A grinding-mill comprising a cylinder having a tapered inner surface and also having an inlet, a grinding-roll arranged in the cylinder and having a tapered portion corresponding to the taper of the cylinder, said tapered portion being corrugated, a grindingring of hard metal, removably attached to the outlet end of the roller, and a grinding-ring removably attached to the end of the cylinder and surrounding the first-named ring.

2. A grinding-mill comprising a cylinder having a tapered inner surface provided with corrugations, a grinding-roll tapered in both directions from a point between its ends, the tapered portion within the tapered part of the cylinder being corrugated, a spirally-disposed flange on the other tapered portion of said roll, a tapered grinding-ring removably attached to the outlet end of said roll, and a grinding-ring removably attached to the end of the cylinder, the inner surface of said lastnamed ring being conformed in shape to the exterior surface of the first-named ring.

3. In a grinding-mill, the combination with a tapered grinding-roll and a cylinder in which the roll operates,of a hard-metal conical grindre0,4s1

ing-ring on the outer end of said roll, and a hard-metal grinding-ring on the outlet end of the cylinder surrounding the first-named ring and conforming in shape thereto, the taper pitch of said rings being greater than the pitch of the roll-taper.

4. A grinding-mill comprising a cylinder, a grinding-roll arranged therein, a hopper at the outlet end of the cylinder, a shaft on which the roll is mounted, the said shaft being extended through the rear Wall of the hopper, brackets on said hopper, a bearing-box for the shaft, adjustable in said brackets, a frame extended rearward from the bearing-box, a block in which the end of the shaft engages, a screw passing through an opening in the end wall of said frame, and also passing loosely through said block, a nut in which said screw operates, means for preventing rotary motion of the nut, and a spring arranged between said nut and said block.

In testimony whereof I have signed my name to th's specification in the presence of two subscribing witnesses.

GEORGE O. PRENZEL.

WVitnesses:

J NO. A. NOLAN, JOHN Gr. NIeHoLs. 

